A process of manufacturing a semiconductor device uses a batch type heat treatment system that batch-performs film formation processing, oxidation treatment, or diffusion treatment of a plurality of objects to be processed, for example, a plurality of semiconductor wafers. In the batch type heat treatment system, although it is possible to efficiently process a semiconductor wafer, it is difficult to uniformly heat-treat the plurality of semiconductor wafers.
To secure the uniformity on heat treatment of the semiconductor wafers, a heat treatment apparatus that automatically regulates an outdoor temperature was proposed. Such heat treatment apparatus controls the outdoor temperature introduced into a heater to become constant.
However, in a heater used to regulate a temperature, power of the heater and power of a heater disposed in an adjacent zone cause interference to each other, and thus, the power of the heater is increased or decreased by the power of the heater disposed in the adjacent zone. Also, recent energy saving heaters are very low in power output compared to conventional heaters, and thus, even when a temperature is slightly regulated, power of the recent energy saving heater can be saturated (0% or 100%). If power of a heater is saturated, it is unable to accurately control a temperature, causing a reduction in reproducibility of heat treatment. For this reason, in regulating a temperature of a heater, it is required to set the temperature in consideration of power of the heater.
As described above, since it becomes difficult to regulate a temperature of a heater, a manipulator of a heat treatment system performs fine regulation on the basis of an experience or a sense, and thus, a heat treatment system and a heat treatment method are needed in which even a manipulator, having no knowledge or experience of a heat treatment system or a process, can easily regulate a temperature without saturating power of a heater.